Method and apparatus for application specific medium access control and physical layer network behavior manipulation

ABSTRACT

The behavior of devices on a network can be modified on the medium access control level to achieve various application level objectives. These types of modifications can include organizing the behavior of transmitting stations to achieve various objectives (e.g., equal allocation of airtime on a wireless network link) for the transmission of data back to those stations&#39; access points. Other modifications, such as changing various stations&#39; maximum data transmission size and modifying an access point&#39;s amplifier gain could also be made.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation of, and claims the benefit of, U.S.non-provisional patent application Ser. No. 16/400,254, filed on May 1,2019, which itself is a non-provisional of, and claims the benefit of,provisional patent application 62/665,070, filed May 1, 2018. Each ofthose applications is hereby incorporated by reference in its entirety.

FIELD

The technology disclosed herein can be applied to the operation ofcommunication networks comprising a plurality of physical devicesconnected via a shared medium. In certain preferred embodiments,application layer logic may control medium access control (MAC) behavioron an 802.11 wireless network to prevent network performance from beingdegraded by stations with relatively low transmission speeds.

BACKGROUND

When a communication network comprising multiple devices operates over ashared medium (e.g., a portion of wireless spectrum, a single physicalwire, etc.) an issue that often arises is that simultaneoustransmissions by multiple devices can interfere with each other. Toaddress this, various approaches to avoiding collisions have beenimplemented. However, these remedial measures often come with their owndrawbacks. For example, in some cases the systems used to control whenvarious devices can transmit data can have the (un)intended consequenceof allowing slower devices to dominate the network. This can beparticularly problematic in the case of wireless networks, where issueslike interference and attenuation of signal strength with distance cansignificantly degrade the effective transmission speeds of transmittingdevices. Accordingly, there is a need for improved technology formanaging access to a shared communication medium used by a networkcomprising multiple devices. Additionally, there is a particular needfor improved technology for managing the transmission of data fromremote devices on a wireless communication network without allowingthose devices to dominate or degrade the performance of the network'sshared wireless link.

SUMMARY

Disclosed herein is technology which can be implemented in a variety ofmanners, including systems and methods for modifying the medium accesscontrol behavior of a wireless network to achieve various applicationlevel objectives. These modifications made include deploying variousspecialized software on access points, stations, or on other devices.Other ways of implementing the disclosed technology are also possible,and so the material set forth in this summary should be understood asbeing illustrative only, and should not be treated as limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings and detailed description which follow are intended to bemerely illustrative and are not intended to limit the scope of theinvention as set forth in the appended claims.

FIG. 1 depicts an environment in which aspects of the disclosedtechnology could be deployed.

FIG. 2 depicts a scenario that could take place on a wireless networkcomprising two stations and an access point.

FIG. 3 depicts a scenario that could take place on a wireless networkcomprising two stations and an access point.

FIG. 4 depicts a scenario that could take place on a wireless networkcomprising two stations and an access point.

FIG. 5 depicts a process that could be used by an access point todetermine whether (and to which station) to send a CTS.

FIG. 6 depicts an access point auto-tuning process that could be used insome embodiments.

FIG. 7 depicts an exemplary table that could be used access pointauto-tuning.

DETAILED DESCRIPTION

Disclosed herein is novel technology which can be used for a variety ofpurposes, including management of access to a communication media(corresponding to the MAC sublayer of the data link layer in the OSIreference model) in a wireless communication network. As set forthherein, in some preferred embodiments, the disclosed technology may beused to operate an 802.11 network in a manner that uses applicationlevel considerations to avoid problems with standards in the 802.11family (e.g., communication channels being dominated by lower performingdevices). While, as described herein, such a network may be used forpurposes such as streaming video data captured during a football game orother sporting event, it will be apparent to one of ordinary skill inthe art that aspects of the disclosed technology can be applied in othercontexts and for other uses. Accordingly, the disclosure set forthherein should be understood as being illustrative rather than limitingon the scope of protection provided by this or any related document.

Turning now to the figures, FIG. 1 provides a high level illustration ofan exemplary environment in which some embodiments of the disclosedtechnology may be deployed. In that figure, a number of players withinstrumented helmets [101-107] are engaged in a football game officiatedby a number of officials with instrumented hats [120-122] on a footballfield [108]. As set forth below, these instrumented helmets [101-107]and instrumented hats [120-122] could be implemented in a variety ofmanners to enable the capture and transmission of video data during thefootball game. Exemplary instrumented helmets and hats are provided inU.S. Pat. No. 9,930,083 to McLennan et al. for a Method and Apparatusfor an Interchangeable Wireless Media Streaming Device, the disclosureof which is incorporated by reference herein. Consistent with theterminology generally used with reference to 802.11 networks, in thisdisclosure the instrumented hats and helmets of FIG. 1 may be referredto as “stations.”

The environment illustrated in FIG. 1 also includes a plurality ofaccess points [109-114]. In practice, these access points [109-114] willpreferably use a wireless communication channel to receive data from theinstrumented helmets [101-107] and hats [120-122] and to sendinstructions to those helmets and hats regarding when and how that datashould be transmitted and/or stored. The access points [109-114] willalso preferably generate log files indicating any problems with thesecommunications, such as dropped packets or interference on a particularchannel.

In addition to communicating wirelessly with the instrumented helmets[101-107] and hats [120-122], the access points [109-114] willpreferably also communicate over a wired network [115] with a pluralityof communication servers [116-118]. In operation, the communicationservers [116-118] will preferably convert the data from the instrumentedhelmets [101-107] and hats [120-122] into video streams suitable fordisplay to a user, such as by decompressing the data and outputting iton a specified HDMI port, and/or performing other tasks such as applyingsmoothing functions and otherwise processing the video data.

In the environment depicted in FIG. 1, in addition to being used forcommunications between the access points [109-114] and the communicationservers [116-118], the wired network [115] would also preferably be usedfor communications with a command and control computer [119]. Inoperation, the command and control computer [119] would preferably beused to generate commands which would cause the other devices depictedin FIG. 1 to operate in a manner which is consistent with the goals ofthe particular application for which the disclosed technology is beingdeployed. Additionally (or alternatively) in some embodiments a commandand control computer [119] may be configured to control communicationsbetween the access points [109-114] and the various stations (i.e.,instrumented helmets [101-107] and instrumented hats [120-122]) tooptimize the performance of the wireless network.

As an example of how performance of a wireless network operating in theenvironment of FIG. 1 could be optimized, consider the scenario depictedin FIG. 2. In that figure, two stations—station 1 [207] and station 2[208]—have data (e.g., a portion of a video stream) to communicate whichis stored in queues [202] on those stations. Additionally, in FIG. 2,one of the stations, station 2 [208], has transmitted (i.e., sent out awireless signal encoding) a request to send (RTS) frame [203] that isintended to reserve the wireless medium used by the stations and theaccess point [209] for the duration of time necessary to transmitstation 2's data [204]. The other station, station 1 [207], has not yettransmitted its RTS frame [205] or its data [206], and so both its RTSframe [205] and data [206] remain in its queue [201].

In some cases, a scenario such as shown in FIG. 2 would be followed bythe access point [209] receiving station 2's RTS frame [203], andtransmitting a clear to send (CTS) frame specifying that station 2 [208]was authorized to transmit its data [204]. This CTS frame would alsoprevent the remaining stations from transmitting during the periodreserved for station 2 [208], thereby avoiding interference caused bysimultaneous transmissions. Then, after that period had elapsed, anotherstation (e.g., station 1 [207]) could transmit its own RTS frame, whichwould be followed by that station transmitting its own data once acorresponding CTS had been sent by the access point [209]. This processcould continue to iterate with each of the stations with data totransmit requesting to reserve the wireless link and then transmittingthat data once authorized by the access point.

However, in other cases a scenario such as shown in FIG. 2 may proceeddifferently. For example, consider a scenario in which the access point[209] does not receive the RTS [203] from station 2 [208] (e.g., due tointerference) and station 1 [207] sends its own RTS [205] (e.g., becausestation 1 [207] also did not detect station 2's RTS [203], or becausestation 1 [207] did detect station 2's RTS [203] but did not detect acorresponding CTS within an interframe period it was configured to waitbetween frames for collision avoidance). This state of affairs isillustrated graphically in FIG. 3.

In a scenario such as shown in FIG. 3, if the access point [209]receives the RTS [205] from station 1 [207] and responds by sending aCTS reserving the link for station 1 for the period station 1 needs totransmit its data [206], the result could be that station 2 [208] wouldbe prevented from sending its data [204]. This could be problematic,especially if this was not the first time that station 2 [208] had beenunsuccessful in reserving time to send its data [204].

To address this type of scenario, some systems implemented based on thisdisclosure could configure the access point [209] (or, preferably, acomputer connected to the access point, such as the command and controlcomputer [119] of FIG. 1) to identify situations where it shouldpreemptively reserve the wireless link for a station that had not sentan RTS (or which has sent an RTS that has not been detected). Forexample, in some cases software running on an access point could trackwireless link level parameters (e.g., disproportionate use of thewireless link, dropped frames, connection strength) and/or applicationlevel parameters (e.g., which devices are most likely to have data thatwould be of interest to an end user). This information could then beused to identify if a station has data to transmit (e.g., a camera on ahelmet of a player involved in a particularly exciting play) but hasbeen having difficulty in transmission (e.g., because they have moredropped frames), and preemptively send a CTS for that station even if noRTS for that station had been received. Preferably, this CTS willspecify a relatively short duration for the wireless link to be reservedfor the relevant station (e.g., long enough for that station to send anew RTS message, but not long enough for it to send a complete datapayload), and the relevant station will respond with a new RTS messagerequesting enough time to send its data.

An illustration of this type of scenario is provided in FIG. 4. In thatfigure, the access point [209] sends a CTS [210] to station 2 [208]despite not detecting station 2's RTS [203]. Station 2 [208] would thenpreferably determine that the CTS [210] was sent preemptively (e.g.,because it didn't reserve the transmission medium for enough time forstation 2 [208] to transmit its data [204]) and respond by generating anew RTS [211] requesting sufficient time for station 2 [208] to transmitits data [204]. When this new RTS [211] was received by the access point[209] (which would be less likely to be prevented due to interferencesince the CTS [210] would have cleared the wireless link for station 2[208] to transmit the new RTS), the access point [209] could reply witha new CTS [212] allocating the wireless link to station 2 [208] forenough time for that station to transmit its data [204]. In this way,station 2 [208] could be allowed to transmit its data even though theaccess point [209] may not have detected station 2's original RTS [203]and may having pending RTS messages from other stations with strongersignals (e.g., station 1).

Of course, it should be understood that the above discussion of thescenarios of FIGS. 2-4 is intended to be illustrative only, and thatvariations on the above discussion could easily be implemented by thoseof ordinary skill in the art in light of this disclosure. For example,in some embodiments, as an alternative to (or in addition to) case bycase determination such as described above, an access point may usepreemptive CTS messages to more systematically prioritize and structurecommunications from its connected stations. To illustrate, consider FIG.5, which illustrates a process that could be used by an access point todetermine whether (and to which station) to send a CTS. This process,which may be run on a loop by the access point, begins by updating [501]values representing expected backlogs for data to be transmitted by eachof the stations connected to the access point. This updating [501] mayinclude, for a station that has transmitted data since the previousupdate, reducing that station's expected backlog by the amount of thetransmitted data. The updating [501] may also include estimating theamount of data that had been generated but not transmitted by eachstation since the previous update. For example, an embodiment of thedisclosed technology deployed in an environment such as shown in FIG. 1could estimate the amount of data generated but not transmitted by theinstrumented helmets [101-107] by assuming that the helmets werecapturing video data continuously and then using the parameters for thatvideo capture (e.g., framerate, bit depth, etc.) to determine the likelyamount of data represented by the captured video.

Additionally, in some embodiments that implement a process such as shownin FIG. 5, updating [501] may account for factors other than simply theamount of data (expected to be) generated and received. For example, inan embodiment where the connected stations were configured to bufferdata for transmission, an access point may be configured to not increasethe expected backlog for a station once that station's buffer limit wasreached even if no new data was received from that station. Similarly,in some embodiments, if an access point sends a CTS to a station anddoesn't receive any data in return, the access point may be configuredto assume that (despite expectations) that station may not have data totransmit and so may clear the expected backlog value for that station.As example of another type of variation, in some embodiments,application level logic may indicate that data a station is collectingis unlikely to be of any interest (e.g., that station is an instrumentedhat for a referee observing a part of a football field that is notinvolved in the current play) and may treat the expected backlog forthat station as zero to reflect that it could be expected to have nodata worth transmitting (as opposed to no data at all). Accordingly, inlight of these (and other) modifications that could be made to theupdating [501] in a process such as shown in FIG. 5, the discussion ofupdating [501] should be understood as illustrative only, and should notbe treated as limiting even on embodiments which do include such anactivity.

Continuing with the discussion of FIG. 5, in an embodiment followingthat process, after the expected backlogs have been updated [501], atransmission priority can be determined [502] for each of the connectedstations. This transmission priority could be determined in a mannersimilar to that discussed above for determining if a preemptive CTSmessage should be sent to a device, though in some embodiments thevarious stations' expected backlogs may also be considered (e.g., anaccess point could be configured to increase a station's priority if ithad a larger expected backlog). Finally, after determining thetransmission priorities, a preemptive CTS message similar to thatdiscussed in the context of FIG. 4 could be sent [503] to the stationwhose transmission priority was highest. In this way, by appropriatelytweaking the updating [501] and transmission priority determination[502], the disclosed technology could control transmissions fromstations to achieve whoever objectives (e.g., prioritized throughput forstation transmissions, equal or prioritized airtime for the variousdevices, etc.) were seen as most appropriate in its particular context.

Of course, it should be understood that controlling access to acommunication link through methods such as preemptive CTS messages asdescribed above is not the only way in which the disclosed technologycould allow users to customize the behavior of a network to achievevarious objectives. As an example of another type of modification whichcould be made using aspects of the disclosed technology, consider thepossibility for modifying the maximum amount of data that would beincluded in any particular transmission (the MTU). As shown below intable 1, using the same MTU for all devices on a network can result indata transmission taking a much greater time for slower than fasterstations.

TABLE 1 Transmission times for constant size 1500 B MTU by stations withdifferent connection speeds. Transmission time for 1500 B MTU ConnectionSpeed (Mbps) (microseconds) 300 40 150 80 75 160

This can be detrimental for various reasons, such as allowing thetransmission link to be dominated by slower devices (if the network wasimplemented to allow the same number of MTUs to be transmitted by eachdevice), to making the slower devices wait an inordinate amount of timebefore they would be allowed to transmit at all (if the network wasimplemented to balance the time each device was allowed to use thecommunication link).

To address this, some systems implemented based on the disclosedtechnology could be configured to modify the MTUs for the variousstations on a network based on those stations' connection speeds. Forexample, an access point could be configured to track the connectionspeeds of the stations it was connected to and to send instructions tosoftware on those stations instructing them to modify their MTUs so thatthe clock time taken by each station for transmitting one of its MTUswould be the same. For instance, the fastest station connected to anaccess point may be given the highest MTU permitted by the underlyingnetwork protocol (e.g., 2400B in an 802.11 network) and the otherstations may have their MTUs scaled based on the time it would take thefastest station to transmit one of its MTUs. An example of how thiscould be reflected on a network with stations having three differenttransmission speeds is provided below in table 2.

TABLE 2 Exemplary variations in MTU sizes to equalize MTU transmissionclock times. Transmission time Connection Speed for 1 MTU (Mbps) MTUsize (bytes) (microseconds) 300 2,400 64 150 1,200 64 75 600 64

Of course, it should be understood that MTU modification for clock speedequalization as described above is only one example of how MTUs might bemodified in systems implemented based on this disclosure, and should notbe treated as implying limits on the types of MTU modificationscontemplated by the inventors. For instance, in some implementations,rather than modifying MTUs to equalize transmission times acrossdevices, factors similar to those discussed above in the context ofdetermining whether to send a preemptive CTS could also be used indetermining a desired MTU for a particular station (e.g., factors thatwould be used to assign a higher priority for data from a particularstation could also be used to increase the desired MTU for thatstation). Similarly, in some implementations, rather than scaling MTUsfor slower devices in a linear manner based on the MTU for the fastestdevice, MTUs for slower devices have different scaling relationships,such as logarithmic or polynomial relationships, to the MTU for thefastest devices. Alternatively (or as an additional feature), someimplementations may offer a user the ability to manually indicate thatan MTU should be increased or decreased for a particular device, such asif it appears that that device is being starved. Accordingly, thediscussion above of manners in which MTUs may be modified in variousembodiments should be understood as being illustrative only and, likethe description of preemptive CTS messages, should not be treated aslimiting.

It should also be understood that, while the discussion of preemptiveCTS messages and modifications to MTUs focused on changes to stationbehavior, some implementations of the disclosed technology may also (oralternatively) modify access point behavior to improve the ability of anetwork to achieve the objective(s) for which it is deployed. Toillustrate, consider the possibility of modifying an access point'ssignal strength in a manner that will decrease the access point'scoverage, but that may increase the transmission speed for stationscloser to the access point (e.g., by decreasing an access point'samplifier gain when its connected stations are close enough that ahigher gain might degrade their communication). In embodiments wherethis type of access point behavior modification is present, one way itmay be implemented would be to begin with an access point at maximumtransmission power, and then automatically adjusting the access point'stransmission power to provide an environment in which all stationsconnected to that access point are able to negotiate as fast a data rateas possible. An example of a process that could be used for this kind ofaccess point auto-tuning is provided in FIG. 6, discussed below.

In the process of FIG. 6, initially (e.g., on system startup) thetransmission power of an access point can be set [601] to its maximumintensity. Then, once all stations allocated to that access point haveestablished connections, each of those stations could report [602]various data regarding their connections, such as received signalstrength (reported in dBm), and signal to noise ratio. From thisinformation, the stations with highest and lowest received signalstrength (RSSI) measurements could be identified [603] and theinformation from those stations could be used to determine if anychanges should be made to the transmission power of the access point.For example, in some embodiments, a check [604] could be made of whetherit would be acceptable to lower the access point's transmission power.Such a check [604] could make use of a table such as shown in FIG. 7, todetermine if the lowest RSSI station had a SNR lower than the minimumSNR given the MCS index for its current RSSI and lowering thetransmission power for the access point would not result in the highestRSSI station going to a lower MCI index. Additionally, in someembodiments such a check [604] could include an empirical component. Forexample, in some embodiments, stations may be operated using driversthat would continuously try to negotiate a higher MCS index. In thiscase, a determination of whether lowering transmission power wouldresult in the highest RSSI station going to a lower MCS index could bemade by lowering the transmission power and then, if highest RSSIstation lowered its MCS index, reverting to the previous (higher) signalstrength so that that station's MCS index would not be unnecessarilyimpacted. However, the check [604] was made, if it was determined thatit would be acceptable to lower the access point's transmission power,then the transmission power could be lowered [605].

A similar determination [606] could also be made of if the accesspoint's transmission power was too low. For example, a table such asshown in FIG. 7 could be used to check if the SNR for the access pointwith the lowest RSSI was greater than the minimum SNR for the nexthighest MCS index. If so, the determination [606] could be treated asindicating that the transmitting power of the access point was too low,and the transmitting power could accordingly be increased [607]. Thisprocess, (i.e., reporting [602] RF parameters, followed by lowering[605] or raising [607] the access point's transmission power asappropriate) could then be repeated periodically (e.g., every second),thereby allowing a system implementing this aspect of the disclosedtechnology to dynamically adjust transmission behavior in a manner thatoptimizes performance of the network in real time. Additionally, when anew device is added [608] to the access point (see U.S. Pat. No.9,930,083 for examples of situations where this may take place), theaccess point's behavior could effectively reset, reverting to maximumpower and then auto-adjusting as described above so that itstransmission behavior was appropriate for all of the stations, includingthe one that was newly added.

Of course, modifications on the auto-adjustment as described above arepossible, and could be implemented by those of ordinary skill in the artwithout undue experimentation in light of this disclosure. For example,instead of simply maximizing the success of all stations (i.e., bychecking whether transmission power could be raised or lowered based onits impact on the lowest RSSI station), it is possible that someembodiments could weight the impact of changes on various stations basedon the priority of the streams being transmitted by those stations.Similarly, in some embodiments, access point behavior could be adjustedto maximize total bandwidth for all connected stations, rather thanfocusing on the minimum and maximum RSSI stations as described above.Other types of variation, such as variations in devices that actuallyperform various processing tasks described herein, are also possible.For instance, while the above description tended to refer to an accesspoint making various changes or performing various processes, it ispossible that, in some implementations, processing described above asbeing performed on an access point may be performed on a separate device(e.g., a command and control computer [119], or a dedicated computerconfigured to manage network traffic) with only the output communicatedto the access point for transmission to the relevant station(s).

In light of the potential for variations and modifications to thematerial described explicitly herein, the disclosure of this documentshould not be treated as implying limits on the protection provided bythis document or any related document. Instead, the protection providedby a document which claims the benefit of or is otherwise related tothis disclosure should be understood as being defined by its claims,when the terms in those claims which are explicitly defined under the“Explicit Definitions” heading are given their explicit definitions, andwhen all other terms are given their broadest reasonable interpretationas shown by a general purpose dictionary. To the extent that theinterpretation which would be given to the claims based on the abovedisclosure is in any way narrower than the interpretation which would begiven based on the explicit definitions under the “Explicit Definitions”heading and the broadest reasonable interpretation as provided by ageneral purpose dictionary, the interpretation provided by the explicitdefinitions under the “Explicit Definitions” heading and broadestreasonable interpretation as provided by a general purpose dictionaryshall control, and the inconsistent usage of terms in the specificationshall have no effect.

Explicit Definitions

When used in the claims, “based on” should be understood to mean thatsomething is determined at least in part by the thing that it isindicated as being “based on.” When a claim is written to requiresomething to be completely determined by a thing, it will be describedas being “based EXCLUSIVELY on” the thing.

When used in the claims, a “computer” should be understood to refer to agroup of devices (e.g., a device comprising a processor and a memory)capable of storing and executing instructions for performing one or morelogical and/or physical operations on data to produce a result. A“computer” may include, for example, a single-core or multi-coremicrocontroller or microcomputer, a desktop, laptop or tablet computer,a smartphone, a server, or groups of the foregoing devices (e.g., acluster of servers which are used in combination to perform operationson data for purposes such as redundancy and availability). In theclaims, the word “server” should be understood as being a synonym for“computer,” and the use of different words should be understood asintended to improve the readability of the claims, and not to imply thata “sever” is not a computer. Similarly, the various adjectives precedingthe words “server” and “computer” in the claims are intended to improvereadability, and should not be treated as limitations.

When used in the claims, “computer readable medium” should be understoodto refer to any object, substance, or combination of objects orsubstances, capable of storing data or instructions in a form in whichthey can be retrieved and/or processed by a device. A computer readablemedium should not be limited to any particular type or organization, andshould be understood to include distributed and decentralized systemshowever they are physically or logically disposed, as well as storageobjects of systems which are located in a defined and/or circumscribedphysical and/or logical space. Examples of computer readable mediumsincluding the following, each of which is an example of a non-transitorycomputer readable medium: volatile memory within a computer (e.g., RAM),registers, non-volatile memory within a computer (e.g., a hard disk),distributable media (e.g., CD-ROMs, thumb drives), and distributedmemory (e.g., RAID arrays).

When used in the claims, to “configure” a computer should be understoodto refer to providing the computer with specific data (which may includeinstructions) and/or making physical changes in the computer (e.g.,adding peripherals) which can be used in performing the specific actsthe computer is being “configured” to do. For example, installingMicrosoft WORD on a computer “configures” that computer to function as aword processor, which it does using the instructions for Microsoft WORDin combination with other inputs, such as an operating system, andvarious peripherals (e.g., a keyboard, monitor, etc. . . . ).

When used in the claims, “first,” “second” and other modifiers whichprecede nouns or noun phrases should be understood as being labels whichare intended to improve the readability of the claims, and should not betreated as limitations. For example, references to a “firstcommunication server” and a “second communication server” should not beunderstood as requiring that one of the recited servers precedes theother in time, priority, network location, or any other manner.

When used in the claims, a “means for improving application layerfunctionality by modifying default medium access control layer ordefault physical layer operation of the wireless network” should beunderstood as a means plus function limitation as provided for in 35U.S.C. § 112(f), in which the function is “improving application layerfunctionality by modifying default medium access control layer ordefault physical layer operation of the wireless network” and thecorresponding structure is a computer coupled to a transceiver (whichcould be physically disposed in a common housing with the computer, orcould be disposed in a separate housing from the computer) andconfigured to perform one or more of the preemptive CTS processesillustrated in FIGS. 2-5 and described in the corresponding text, theMTU modification processes described in the text accompanying tables 1and 2, and/or the dynamic signal strength modification processes asillustrated in FIG. 6 and described in the text corresponding to thatfigure.

When used in the claims, a “means for sending preemptive clear to sendframes to particular stations from the plurality of stations” should beunderstood as a means plus function limitation as provided for in 35U.S.C. § 112(f), in which the function is “sending preemptive clear tosend frames to particular stations from the plurality of stations” andthe corresponding structure is a computer coupled to a transceiver andconfigured to perform preemptive CTS process illustrated in FIGS. 2-5and described in the corresponding text.

When used in the claims, a “means for modifying maximum transmissionunits for particular stations” should be understood as a means plusfunction limitation as provided for in 35 U.S.C. § 112(f), in which thefunction is “modifying maximum transmission units for particularstations” and the corresponding structure is a computer coupled to atransceiver and configured to perform MTU modification processes asdescribed in the text accompanying tables 1 and 2.

When used in the claims, a “means for auto-tuning gain based on signalto noise ratio data” should be understood as a means plus functionlimitation as provided for in 35 U.S.C. § 112(f), in which the functionis “auto-tuning gain based on signal to noise ratio data” and thecorresponding structure is a computer coupled to a transceiver andconfigured to perform dynamic signal strength modification processes asillustrated in FIG. 6 and described in the text corresponding to thatfigure.

When used in the claims, a “set” should be understood to refer to agroup of one or more things of similar nature, design or function. Thewords “superset” and “subset” should be understood as being synonyms of“set,” and the use of different words should be understood as intendedto improve the readability of the claims, and not imply differences inmeaning.

What is claimed is:
 1. A system comprising a wireless network comprisingan access point and a plurality of stations, wherein: a) each stationfrom the plurality of stations is configured to transmit data capturedby a sensor connected to that station wirelessly to the access pointover a shared medium; b) the access point is configured with anon-transitory computer readable medium having stored thereoninstructions adapted to, when executed, cause the access point toimprove application layer functionality by modifying default physicallayer operation of the wireless network.
 2. A method of operating awireless network comprising an access point and a plurality of stations,the method comprising: a) each station from the plurality of stationscapturing data using a sensor connected to that station; b) each of oneor more stations from the plurality of stations transmitting datacaptured by the sensor connected to that station to the access pointover a shared medium, wherein each station from the plurality ofstations is configured to transmit data captured by the sensor connectedto that station to the access point over the shared medium; and c) theaccess point improving application layer functionality by modifyingdefault physical layer operation of the wireless network.
 3. A machinecomprising: a) a plurality of stations, wherein each station from theplurality of stations is configured to transmit data captured by asensor connected to that sensor over a wireless network; and b) a meansfor improving application layer functionality by modifying defaultmedium access control layer or default physical layer operation of thewireless network, wherein the means for improving application layerfunctionality by modifying default medium access control layer ordefault physical layer operation of the wireless network is a means forauto-tuning gain based on signal to noise ratio data.
 4. The system ofclaim 1, wherein improving application layer functionality by modifyingdefault physical operation of the wireless network comprises performingdynamic modification of signal strength for the access point.
 5. Themethod of claim 2, wherein the access point improving application layerfunctionality by modifying default physical layer operation of thewireless network comprises performing dynamic modification of signalstrength for the access point.